1. Field of the Invention
The present invention generally relates to hydrotherapy spas, and more specifically to a water injection system including a valve which is driven by inlet water flow and distributes the water to injection nozzles which are spaced around the spa in a pulsating manner.
2. Description of the Related Art
A hydrotherapy spa, also known as a hot tub or a Jacuzzi, is provided with a number of nozzles or jets around its periphery for injection of a massaging mixture of water and air into the main body of water in the spa. The injected bubbling water has a pleasant, soothing and therapeutic effect.
Water from a suitable source is conventionally supplied via a manifold valve to all of the nozzles in a continuous manner. However, the beneficial effects of the injected water are enhanced if the water is supplied in a pulsating, rather than a continuous manner.
Various expedients have been conceived for introducing pulsation into the injected water, including intermittently blocking and unblocking the inlet water or air flow to the nozzles, and intermittently disabling venturis which cause aspiration of air into the water flow through the nozzles.
A typical prior art pulsating water injection system is describe in U.S. Pat. No. 4,508,665, entitled "RETROFIT PULSATOR APPARATUS AND METHOD FOR AN AIR/WATER MIXER OF A SWIMMING POOL, THERAPY TUB, SPA OR THE LIKE", issued Apr. 2, 1985 to R. Spinnett, which discloses a retrofit assembly for a spa nozzle including a rotor which is driven by the inlet water flow and intermittently interrupts the outlet water flow.
Prior art systems such as disclosed by Spinnett require a separate pulsator unit for each nozzle, increasing the complexity, cost and maintenance of the spa. In addition, since the pulsator units operate independently, they cannot be synchronized to provide a rippling effect in which the pulsation appears to rotate around the spa.